The local Honda dealer had told the previous owners that the hybrid battery was dead, and would cost ~$3000+ to replace with a new one.

Fortunately for me, they thought a $3k+ repair bill was a bit steep for an 11 year-old car with 269,000 km (167k mi.) on it. So they traded it in at a different used car lot out in the country, and the lot owner was pleased to eventually unload that defective, weird little car on me.

Code red:

The car had a stored P1449 code. From what I've been able to gather, it's set for a number of potential IMA battery pack issues:

Resetting the CEL and IMA lights caused the hybrid functions to return to normal!

But only for a while.

The hybrid battery gauge would show recharging while driving or idling, and the electric assist, regenerative coasting/braking, and idle-stop functions worked fine.

But after a while (particularly after sustained charging or assist), the lights would come on again and the hybrid functions would cease.

A "crippled" hybrid that can still get 80+ mpg

Honda designed the car to work even with the hybrid functions disabled. The engine even has a "back-up", conventional 12 volt starter. (Normally it's started instantly & quietly via the IMA motor/generator.)

So I drove the car from July through November, minus the hybrid stuff, and managed to attain 80+ MPG (US) / 2.7 L/100 km over thousands of kilometers and 3 tanks of gas. How? Most of my travels were "driving with load" at moderate speeds (~80 km/h) on secondary highways (mostly flat to slightly rolling terrain) where the car could be held in lean burn mode for extended periods.

But the hybrid stuff is way cool

I could just leave the hybrid stuff disabled, and continue getting phenomenal fuel economy forever. Even without the hybrid functions, the Insight is a marvel of efficiency engineering: light, highly aerodynamic, efficient 3-cylinder gas engine with lean burn, and tall gearing.

I will never make back the money in added fuel savings that it will cost to repair, even if the cost is only in the low-mid hundreds of dollars.

But ... the hybrid stuff is teh geeky coolness. So I'm going to look at fixing it anyway. DIY, baby!

This thread will document the adventure.

I'll be pulling the pack out this weekend, and I've got myself a $80 NiMH battery/cell analyzer from eBay. Step one is gathering data/characterizing the health of the cells in this pack.

Your posts are among the most interesting and well written Metro- Thanks!

Best of luck on your endeavor. I tried and failed to repair a malfunctioning Roomba battery. I was able to locate 2 cells that were below voltage threshold and replace them, but alas, the darned robot still doesn't like the battery. I ended up buying a new one from Ebay for about $25.

I'll be following your progress since I have the same situation with my HCH. Are there known reliability issues with the Super Brain charger? Seems I've read that once or twice. Are there any other chargers suitable for this task?

Also, regarding your point about never recovering the expense of repairing the pack, don't overlook the increased resale value should you ever sell the car. Especially since I'm assuming you got a great deal on it due to the battery problems. I could drive my car forever as it sits now with no electric assist, but I'd take a huge hit if I ever tried to sell it like that. Plus the car is a LOT more fun to drive with electric assist, so there's that to consider as well.

Yes. I've read more than a couple of accounts of the unit failing. Maybe they're not really designed for the marathon use that analyzing a hybrid battery pack represents - they're really meant for small capacity batteries for remote control vehicle hobbyists.

I gather it's good advice to keep the unit as cool as possible while using it (even an external fan).

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Are there any other chargers suitable for this task?

I seem to recall the owner of hybrid-battery-repair saying he uses them in his business, and has many of them running simultaneously. He's experienced a few failures but is generally satisfied with them. I'm generally a lazy SOB, so rather than do any further research, I bought what he uses (and Mr Smalls uses, in his battery refurb thread).

Quote:

Also, regarding your point about never recovering the expense of repairing the pack, don't overlook the increased resale value should you ever sell the car.

Absolutely true. I could easily make a handsome profit if I fixed the hybrid battery and sold the car. But that's not in my plans. (I'm good at acquiring junk, not so good at getting rid of junk! )

Quote:

Plus the car is a LOT more fun to drive with electric assist, so there's that to consider as well.

That's the main reason why I'm doing it. I'm looking forward to playing with the hybrid functions, and learning a new set of driving skills & strategies!

Formula: just out of curiosity, have you tried the grid charger approach to balance your pack?

If I had to rely on my vehicle (ie. couldn't afford to pull it off the road for an extended period to tinker with it), I might start with that first.

It's possible you could return it to health without having to go through the tedious process of analyzing the subpacks with the Super Brain (or equivalent).

I'll definitely make/get a grid charger when this process is done anyway, particularly since I don't drive an awful lot. The car sits sometimes for weeks at a time, which is particularly terrible for the pack (cells drift out of balance through different rates of self-discharge).

Also, it will be fun to play at "mini-plug-in-hybrid" with a grid-charger.

Formula: just out of curiosity, have you tried the grid charger approach to balance your pack?

As a matter of fact I have, I don't own one but I did get to give it a grid charging once, for several hours. The assist worked great for a few days, then the P1449 came back, and the usable capacity continued to whither. That tends to make me suspect that there is a weak cell in there somewhere. A grid charger is very expensive, and I'm somewhat reluctant to commit to that if I will still need to tear down the pack and find the bad subpacks.